7 files changed, 115 insertions, 17 deletions

diff --git a/editors/code/package.json b/editors/code/package.json
index 13749a084..3e6ebd7ed 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -104,6 +104,11 @@
                 "category": "Rust Analyzer"
             },
             {
+                "command": "rust-analyzer.viewHir",
+                "title": "View Hir",
+                "category": "Rust Analyzer"
+            },
+            {
                 "command": "rust-analyzer.expandMacro",
                 "title": "Expand macro recursively",
                 "category": "Rust Analyzer"
@@ -275,7 +280,7 @@
                     "default": true,
                     "description": "Whether to ask for permission before downloading any files from the Internet."
                 },
-                "rust-analyzer.serverPath": {
+                "rust-analyzer.server.path": {
                     "type": [
                         "null",
                         "string"
@@ -283,6 +288,14 @@
                     "default": null,
                     "markdownDescription": "Path to rust-analyzer executable (points to bundled binary by default). If this is set, then `#rust-analyzer.updates.channel#` setting is not used"
                 },
+                "rust-analyzer.server.extraEnv": {
+                    "type": [
+                        "null",
+                        "object"
+                    ],
+                    "default": null,
+                    "markdownDescription": "Extra environment variables that will be passed to the rust-analyzer executable. Useful for passing e.g. `RA_LOG` for debugging."
+                },
                 "rust-analyzer.trace.server": {
                     "type": "string",
                     "scope": "window",
@@ -336,7 +349,7 @@
                     "default": {},
                     "markdownDescription": "Optional settings passed to the debug engine. Example: `{ \"lldb\": { \"terminal\":\"external\"} }`"
                 },
-                "rust-analyzer.assist.importMergeBehaviour": {
+                "rust-analyzer.assist.importMergeBehavior": {
                     "markdownDescription": "The strategy to use when inserting new imports or merging imports.",
                     "default": "full",
                     "type": "string",
@@ -650,6 +663,14 @@
                     "default": false,
                     "type": "boolean"
                 },
+                "rust-analyzer.procMacro.server": {
+                    "markdownDescription": "Internal config, path to proc-macro server executable (typically, this is rust-analyzer itself, but we override this in tests).",
+                    "default": null,
+                    "type": [
+                        "null",
+                        "string"
+                    ]
+                },
                 "rust-analyzer.runnables.overrideCargo": {
                     "markdownDescription": "Command to be executed instead of 'cargo' for runnables.",
                     "default": null,
@@ -999,6 +1020,10 @@
                     "when": "inRustProject"
                 },
                 {
+                    "command": "rust-analyzer.viewHir",
+                    "when": "inRustProject"
+                },
+                {
                     "command": "rust-analyzer.expandMacro",
                     "when": "inRustProject"
                 },
diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index 63ab82dde..539e487ec 100644
--- a/editors/code/src/client.ts
+++ b/editors/code/src/client.ts
@@ -6,6 +6,10 @@ import { DocumentSemanticsTokensSignature, DocumentSemanticsTokensEditsSignature
 import { assert } from './util';
 import { WorkspaceEdit } from 'vscode';
 
+export interface Env {
+    [name: string]: string;
+}
+
 function renderCommand(cmd: ra.CommandLink) {
     return `[${cmd.title}](command:${cmd.command}?${encodeURIComponent(JSON.stringify(cmd.arguments))} '${cmd.tooltip!}')`;
 }
@@ -27,14 +31,17 @@ async function semanticHighlightingWorkaround<R, F extends (...args: any[]) => v
     return res;
 }
 
-export function createClient(serverPath: string, cwd: string): lc.LanguageClient {
+export function createClient(serverPath: string, cwd: string, extraEnv: Env): lc.LanguageClient {
     // '.' Is the fallback if no folder is open
     // TODO?: Workspace folders support Uri's (eg: file://test.txt).
     // It might be a good idea to test if the uri points to a file.
 
+    const newEnv = Object.assign({}, process.env);
+    Object.assign(newEnv, extraEnv);
+
     const run: lc.Executable = {
         command: serverPath,
-        options: { cwd },
+        options: { cwd, env: newEnv },
     };
     const serverOptions: lc.ServerOptions = {
         run,
diff --git a/editors/code/src/commands.ts b/editors/code/src/commands.ts
index b12e134ca..c1c9f9754 100644
--- a/editors/code/src/commands.ts
+++ b/editors/code/src/commands.ts
@@ -340,6 +340,61 @@ export function syntaxTree(ctx: Ctx): Cmd {
     };
 }
 
+// Opens the virtual file that will show the HIR of the function containing the cursor position
+//
+// The contents of the file come from the `TextDocumentContentProvider`
+export function viewHir(ctx: Ctx): Cmd {
+    const tdcp = new class implements vscode.TextDocumentContentProvider {
+        readonly uri = vscode.Uri.parse('rust-analyzer://viewHir/hir.txt');
+        readonly eventEmitter = new vscode.EventEmitter<vscode.Uri>();
+        constructor() {
+            vscode.workspace.onDidChangeTextDocument(this.onDidChangeTextDocument, this, ctx.subscriptions);
+            vscode.window.onDidChangeActiveTextEditor(this.onDidChangeActiveTextEditor, this, ctx.subscriptions);
+        }
+
+        private onDidChangeTextDocument(event: vscode.TextDocumentChangeEvent) {
+            if (isRustDocument(event.document)) {
+                // We need to order this after language server updates, but there's no API for that.
+                // Hence, good old sleep().
+                void sleep(10).then(() => this.eventEmitter.fire(this.uri));
+            }
+        }
+        private onDidChangeActiveTextEditor(editor: vscode.TextEditor | undefined) {
+            if (editor && isRustEditor(editor)) {
+                this.eventEmitter.fire(this.uri);
+            }
+        }
+
+        provideTextDocumentContent(_uri: vscode.Uri, ct: vscode.CancellationToken): vscode.ProviderResult<string> {
+            const rustEditor = ctx.activeRustEditor;
+            const client = ctx.client;
+            if (!rustEditor || !client) return '';
+
+            const params = {
+                textDocument: client.code2ProtocolConverter.asTextDocumentIdentifier(rustEditor.document),
+                position: client.code2ProtocolConverter.asPosition(
+                    rustEditor.selection.active,
+                ),
+            };
+            return client.sendRequest(ra.viewHir, params, ct);
+        }
+
+        get onDidChange(): vscode.Event<vscode.Uri> {
+            return this.eventEmitter.event;
+        }
+    };
+
+    ctx.pushCleanup(vscode.workspace.registerTextDocumentContentProvider('rust-analyzer', tdcp));
+
+    return async () => {
+        const document = await vscode.workspace.openTextDocument(tdcp.uri);
+        tdcp.eventEmitter.fire(tdcp.uri);
+        void await vscode.window.showTextDocument(document, {
+            viewColumn: vscode.ViewColumn.Two,
+            preserveFocus: true
+        });
+    };
+}
 
 // Opens the virtual file that will show the syntax tree
 //
diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index 848e92af9..ebe4de1ea 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -1,4 +1,5 @@
 import * as vscode from 'vscode';
+import { Env } from './client';
 import { log } from "./util";
 
 export type UpdatesChannel = "stable" | "nightly";
@@ -13,6 +14,7 @@ export class Config {
     readonly rootSection = "rust-analyzer";
     private readonly requiresReloadOpts = [
         "serverPath",
+        "server",
         "cargo",
         "procMacro",
         "files",
@@ -91,7 +93,10 @@ export class Config {
         return this.cfg.get<T>(path)!;
     }
 
-    get serverPath() { return this.get<null | string>("serverPath"); }
+    get serverPath() {
+        return this.get<null | string>("server.path") ?? this.get<null | string>("serverPath");
+    }
+    get serverExtraEnv() { return this.get<Env | null>("server.extraEnv") ?? {}; }
     get channel() { return this.get<UpdatesChannel>("updates.channel"); }
     get askBeforeDownload() { return this.get<boolean>("updates.askBeforeDownload"); }
     get traceExtension() { return this.get<boolean>("trace.extension"); }
diff --git a/editors/code/src/ctx.ts b/editors/code/src/ctx.ts
index d39864d33..e7585184b 100644
--- a/editors/code/src/ctx.ts
+++ b/editors/code/src/ctx.ts
@@ -24,7 +24,7 @@ export class Ctx {
         serverPath: string,
         cwd: string,
     ): Promise<Ctx> {
-        const client = createClient(serverPath, cwd);
+        const client = createClient(serverPath, cwd, config.serverExtraEnv);
 
         const statusBar = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Left);
         extCtx.subscriptions.push(statusBar);
diff --git a/editors/code/src/lsp_ext.ts b/editors/code/src/lsp_ext.ts
index 5e877ce65..d21a3db86 100644
--- a/editors/code/src/lsp_ext.ts
+++ b/editors/code/src/lsp_ext.ts
@@ -24,6 +24,7 @@ export interface SyntaxTreeParams {
 }
 export const syntaxTree = new lc.RequestType<SyntaxTreeParams, string, void>("rust-analyzer/syntaxTree");
 
+export const viewHir = new lc.RequestType<lc.TextDocumentPositionParams, string, void>("rust-analyzer/viewHir");
 
 export interface ExpandMacroParams {
     textDocument: lc.TextDocumentIdentifier;
diff --git a/editors/code/src/main.ts b/editors/code/src/main.ts
index 282240d84..694da9409 100644
--- a/editors/code/src/main.ts
+++ b/editors/code/src/main.ts
@@ -105,6 +105,7 @@ async function tryActivate(context: vscode.ExtensionContext) {
     ctx.registerCommand('joinLines', commands.joinLines);
     ctx.registerCommand('parentModule', commands.parentModule);
     ctx.registerCommand('syntaxTree', commands.syntaxTree);
+    ctx.registerCommand('viewHir', commands.viewHir);
     ctx.registerCommand('expandMacro', commands.expandMacro);
     ctx.registerCommand('run', commands.run);
     ctx.registerCommand('debug', commands.debug);
@@ -166,6 +167,7 @@ async function bootstrapExtension(config: Config, state: PersistentState): Promi
         }
         return;
     };
+    if (serverPath(config) !== null) return;
 
     const now = Date.now();
     if (config.package.releaseTag === NIGHTLY_TAG) {
@@ -277,7 +279,7 @@ async function patchelf(dest: PathLike): Promise<void> {
 }
 
 async function getServer(config: Config, state: PersistentState): Promise<string | undefined> {
-    const explicitPath = process.env.__RA_LSP_SERVER_DEBUG ?? config.serverPath;
+    const explicitPath = serverPath(config);
     if (explicitPath) {
         if (explicitPath.startsWith("~/")) {
             return os.homedir() + explicitPath.slice("~".length);
@@ -286,16 +288,15 @@ async function getServer(config: Config, state: PersistentState): Promise<string
     };
     if (config.package.releaseTag === null) return "rust-analyzer";
 
-    let platform: string | undefined;
-    if ((process.arch === "x64" || process.arch === "ia32") && process.platform === "win32") {
-        platform = "x86_64-pc-windows-msvc";
-    } else if (process.arch === "x64" && process.platform === "linux") {
-        platform = "x86_64-unknown-linux-gnu";
-    } else if (process.arch === "x64" && process.platform === "darwin") {
-        platform = "x86_64-apple-darwin";
-    } else if (process.arch === "arm64" && process.platform === "darwin") {
-        platform = "aarch64-apple-darwin";
-    }
+    const platforms: { [key: string]: string } = {
+        "ia32 win32": "x86_64-pc-windows-msvc",
+        "x64 win32": "x86_64-pc-windows-msvc",
+        "x64 linux": "x86_64-unknown-linux-gnu",
+        "x64 darwin": "x86_64-apple-darwin",
+        "arm64 win32": "aarch64-pc-windows-msvc",
+        "arm64 darwin": "aarch64-apple-darwin",
+    };
+    const platform = platforms[`${process.arch} ${process.platform}`];
     if (platform === undefined) {
         vscode.window.showErrorMessage(
             "Unfortunately we don't ship binaries for your platform yet. " +
@@ -351,6 +352,10 @@ async function getServer(config: Config, state: PersistentState): Promise<string
     return dest;
 }
 
+function serverPath(config: Config): string | null {
+    return process.env.__RA_LSP_SERVER_DEBUG ?? config.serverPath;
+}
+
 async function isNixOs(): Promise<boolean> {
     try {
         const contents = await fs.readFile("/etc/os-release");